(C6H2(C(CH3)3)CH2O)4Ti(Si(CH3)2)(η6-1,2,4-C6H3(Si(CH3)3)3) | 288094-59-7

• 英文名称: (C6H2(C(CH3)3)CH2O)4Ti(Si(CH3)2)(η6-1,2,4-C6H3(Si(CH3)3)3)
• 英文别名: Ti(1,2,4-(Me3Si)3C6H3)(1,2-alternate dimethylsilyl-bridged p-tert-butylcalix[4]arene dianion)
• CAS: 288094-59-7
• 化学式: C₆₁H₈₈O₄Si₄Ti
• 分子量: 1045.59
• InChiKey: IEGKIGHEYPUTSV-UHFFFAOYSA-L

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
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• 可旋转键数：
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• 环数：
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• sp3杂化的碳原子比例：
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• 拓扑面积：
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• 氢给体数：
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• 氢受体数：
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反应信息

• 作为反应物：
  描述：

  4,4'-二甲基二苯甲酮 、 (C6H2(C(CH3)3)CH2O)4Ti(Si(CH3)2)(η6-1,2,4-C6H3(Si(CH3)3)3) 以 正庚烷 为溶剂， 以92%的产率得到[(1,2-alternate dimethylsilyl-bridged p-tert-butylcalix[4]arene dianion)Ti(OC(p-MeC6H4)2C(p-MeC6H4)2O)]
  参考文献：
  名称：

  Mechanistic Insight into Fragmentation Reactions of Titanapinacolate Complexes

  摘要：

  Reactions between terminal alkynes or aromatic ketones and titanapinacolate complexes (DMSC)Ti(OCAr(2)CAr(2)O) (2, Ar = Ph, and 3, At = p-MeC(6)H(4); DMSC = 1,2-alternate dimethylsilyl-bridged p-tertbutylcalix[4]arene dianion) occur via rupture of the C-C bond of the titanacycle. Thus, reactions of 2 and 3 with terminal alkynes produce 2-oxatitanacyclopent-4-ene or 2-oxatitanacycloheptadiene complexes along with free Ar(2)CO. These compounds have been characterized spectroscopically and by X-ray crystallography. Because metallapinacolate intermediates have been implicated in important C-C bond-forming reactions, such as pinacol coupling and McMurry chemistry, the mechanism of the fragmentation reactions was studied. Analysis of the kinetics of the reaction of (DMSC)Ti{OC(p-MeC(6)H(4))(2)C(p-MeC(6)H(4))(2)O} (3) with Bu(t)C=CH revealed that the fragmentation reactions proceed via a preequilibrium mechanism, involving reversible dissociation of titanapinacolate complexes into (DMSC)Ti(eta(2)-OCAr(2)) species with release of a ketone molecule, followed by rate-limiting reaction of (DMSC)Ti(eta(2)-OCAr(2)) species with an alkyne or ketone molecule.

  DOI：

  10.1021/ja0271577
• 作为产物：
  描述：

  5,11,17,23-tetra-tert-butyl-25,26-dioxo-27,28-(O2SiMe2)-calix[4]arenetitaniumdichloride 、 [2,5-二(三甲基硅烷基)苯基]-三甲基硅烷 在 Mg(C₁₄H₁₀)(C₄H₈O)3 作用下， 以 not given 为溶剂， 以0%的产率得到(C6H2(C(CH3)3)CH2O)4Ti(Si(CH3)2)(η6-1,2,4-C6H3(Si(CH3)3)3)
  参考文献：
  名称：

  Highly Regioselective [2 + 2 + 2] Cycloaddition of Terminal Alkynes Catalyzed by η⁶-Arene Complexes of Titanium Supported by Dimethylsilyl-Bridged p-tert-Butyl Calix[4]arene Ligand

  摘要：

  Two new Ti-eta(6)-arene complexes [(DMSC)Ti{eta(6)-1,2.4-C6H3(SiMe3)(3)}] (6) and [(DMSC)Ti{eta(6)-1,3,5-C6H3Bu3t}] (7) containing 1,2-alternate, Me2Si-bridged p-tert-butylcalix[4]arene (DMSC) ancillary ligand have been synthesized. The solid-state structure of 6 revealed a highly folded arene ligand [with a dihedral angle of 29.7(7)degrees] and suggests that 6 is better described as a 7-titananorbornadiene species. Both 6 and 7 are efficient catalysts for highly regioselective [2 + 2 + 2] cycloaddition of terminal alkynes to yield 1,2,4-substituted benzenes. Kinetic studies of the catalytic [2 + 2 + 2] cycloaddition of Me3SiC equivalent to CH revealed first-order dependence on [6] and [Me3SiC equivalent to CH]; and activation parameters, Delta H-double dagger = 14 kcal/mol, and Delta S-double dagger = -11 cal/mol K, that are consistent with an associative mechanism. The reaction rate is influenced by the steric requirements of both the alkyne and the eta(6)-arene compound. The high selectivity for 1,2,4-substituted benzene may be understood in terms of the directing influence of the DMSC ligand.

  DOI：

  10.1021/ja994543o